In 1954, Denis Mack Smith, who has died aged 97, produced his first book – and his masterpiece – Cavour and Garibaldi 1860: A Study in Political Conflict. Written with verve and style, it unpicks a crucial year in Italian history, undercutting a series of accepted truths concerning Italy’s unification and, in Jonathan Steinberg’s words, telling Italians “what they did not want to hear”.

Denis was a rarity, a true populariser of history, who wrote in a clear, readable and engaging style. His writing was full of quotable lines. He wrote of Cavour that he had “managed to persuade people to back a revolution on the excuse that this was the way to prevent a revolution”.

In 1949, Denis met one of Garibaldi’s daughters in Rome, and she invited him to visit the family home on the island in Caprera. He later said that it was one of the great regrets of his life that he had not been able to do so.

Ridley Scott, the director of Alien, Blade Runner, Gladiator and The Martian, has taken aim at Donald Trump and Boris Johnson over their leadership during the coronavirus pandemic.

Scott, who was born shortly before the second world war, suggested that countries, the UK in particular, should reintroduce rationing because “people are buying so much food and then the food is rotting”.

Scott also said the disparity in the quality of coronavirus coverage across the US news networks was “insane”.

Members of Congress are racing back to Washington, despite social isolation guidelines, out of fear that a lawmaker could delay a Friday vote on the $2.2tn economic stimulus package designed to rush federal aid to workers, businesses and a healthcare system ravaged by the coronavirus.

There is no doubt the law has enough support to pass. The Senate approved the bill in a unanimous vote on Wednesday night. House speaker Nancy Pelosi said she expected broad bipartisan support and Donald Trump has said he would sign it into law.

On Capitol Hill, Massie dismissed concerns about legislators having to fly back to Washington, noting that he chose to drive and suggesting stranded colleagues might “hitch a ride with a trucker”.

Boris Johnson and health secretary Matt Hancock have both tested positive for coronavirus and will have to work leading the government’s efforts to tackle the pandemic in isolation.

Johnson posted a video on Friday morning on Twitter saying he had a temperature and a persistent cough. “I am working from home, I’m self-isolating, and that’s entirely the right thing to do,” he said.

“Fortunately for me the symptoms so far have been very mild so I’ve been able to carry on with the work driving forward the UK response,” he said. “I’ll be continuing to do everything I can to get our carers the support that they need. And I’ll be doing that from here but with no less gusto.”

He was the man who famously unified Germany and ended France's domination of Europe. But new documents found in a dusty town hall reveal that the German chancellor Otto von Bismarck nearly drowned while swimming at the French seaside resort of Biarritz, an event that could have profoundly changed the course of European history.

The rescue of Bismarck - then Prussia's ambitious ambassador in Paris, in his mid-40s - would prove costly for France. Eight years later, in 1870, he masterminded Prussia's swift, crushing defeat of France in the Franco-Prussian war, ending French primacy in Europe. The Iron Chancellor went on to unify Germany, something that had eluded its kings and rulers since Charlemagne.

Bismarck recalled his time in Biarritz, where he met the French emperor Napoleon III, as the happiest of his life. "I have lost the illusion, that we can be happy again in Biarritz," he wrote later to his ailing mistress, who died in 1875 at 35.

Before we leave the centenary year of the outbreak of war in 1914 there’s someone we should talk about. Everyone now knows about the famous Christmas truce and football matches. But this was a war that was meant to have been “over by Christmas” 1914, not dragging on for four blood-soaked years. Plenty share blame for that, but one major culprit who seems to have been conspicuous by his absence in 2014 deserves a name check: Otto von Bismarck.

What Germans got instead was a militarised monarchical autocracy sustained by rampant nationalism and supported by intellectuals of all kinds – sociologist Max Weber later repented his enthusiasm – who should have known better. Parliament was marginalised, the parties manipulated against each other, and Bismarck threatened to resign whenever he was seriously challenged. It was outrageous and it ended in the ruins of Berlin of 1945.

After its humiliations at the hands of Napoleon, 19th century Prussia’s was – even more than under Frederick the Great – a conscious process of self-aggrandisement. Plenty resisted the trend and Bismarck’s “iron and blood” exposition of his realpolitik ambitions in 1862 nearly got him fired before he started. He was not charismatic, soft-spoken, even hesitant, but utterly dominant over his king and even the powerful military, which privately mocked his weakness for uniforms. Try this interview with his biographer Jonathan Steinberg for a flavour of him. “This man means what he says,” Benjamin Disraeli concluded. Scary.

Researchers believe the Indian Ocean Dipole is more clearly influenced by climate change than previously thought

Indian Ocean surface temperatures that helped drive hot and dry conditions in eastern Australia last year were more clearly influenced by climate change than previously thought and are likely to worsen in future, researchers have found.

The Indian Ocean Dipole (IOD) is the difference in temperature between the western and eastern Indian Ocean. When the IOD is in positive mode, warmer waters develop off the Horn of Africa and cooler waters develop off Indonesia. This leads to hotter and drier weather in Australia.

Fashion operates on desire. How we dress feeds off cravings to be different as well as part of a tribe; to be en vogue but ahead of the pack. The message from the high street is that such wishes can be fulfilled, and fast fashion plays on the idea that hunger can be sated immediately. But to overcome such urges we need to reflect on the fragility of our planet. This means accepting that there is a better way to keep the pleasures of fashion open to all parts of society than promoting disposable clothes as desirable. This is not just about the high cost of the £4 dress; luxury retailers such as Louis Vuitton have offered small collections every two weeks.

Fashion shouldn’t cost the earth. But the industry has for too long promoted overconsumption as a good thing. About a fifth of mass-produced clothing does not even sell and ends up being buried, shredded or burned. Garments now account for 8% of global greenhouse gas emissions. Synthetic fibres are being found in Arctic sea ice and in fish.

New research shows that 51% of Britons are opting to purchase expensive but longer-lasting clothes rather than cheaper throwaway items, up from 33% a year ago.

Cognac makers are considering overturning longstanding tradition and turning to new grape varieties, as the main cultivar required to make the spirit struggles with the effects of global warming.

Cognac’s star grape, Ugni blanc, which accounts for 98% of the vines in the Cognac region, is ripening quicker and losing acidity as summers become hotter and drier.

The spirit is, broadly, made from wine that is distilled into a liquid called eau-de-vie and aged in oak casks, often for decades. The result is cognac, with Hennessy, Martell, Courvoisier and Rémy Martin among the best known brands.

The number of new renewable energy projects applying for planning permission reached a four-year high in the UK last year as energy companies raced to meet the rising demand for clean electricity.

The jump in applications last year was the biggest annual increase in recent years and 75% higher than the number of annual planning submissions made three years ago. There were just 154 submissions in 2016, rising to 185 in 2017.

Planning submissions for clean energy projects are expected to rise in the years ahead due to the government’s decision earlier this month to lift a block against subsidising onshore wind projects that was put in place almost five years ago.

Analysis of satellite data reveals astounding loss of 600bn tons of ice last summer as Arctic experienced hottest year on record

Last year’s summer was so warm that it helped trigger the loss of 600bn tons of ice from Greenland – enough to raise global sea levels by 2.2mm in just two months, new research has found.

Glaciers are melting away around the world due to global heating caused by the human-induced climate crisis. Ice is reflective of sunlight so as it retreats the dark surfaces underneath absorb yet more heat, causing a further acceleration in melting.

Nicholas Stern, one of the most prominent global experts on the climate crisis, has urged Boris Johnson to resist calls to postpone vital UN climate talks this year, despite the coronavirus outbreak.

Lord Stern believes any move to postpone the talks would put paid to any hope of making real progress. “At the moment we must just get on with the preparation,” he said. “This is such an urgent challenge and there is so much to do, and so much valuable work that is being done, that we can’t afford to lose the momentum.”

Stern said work had become more difficult because of the virus, but not impossible. Postponing the summit now would effectively put the brakes on at a time when acceleration is needed, he said, and if needs be then a postponement could be discussed after the summer, depending on the situation then.

Electric vehicles produce less carbon dioxide than petrol cars across the vast majority of the globe – contrary to the claims of some detractors, who have alleged that the CO2 emitted in the production of electricity and their manufacture outweighs the benefits.

Across the world, passenger road vehicles and household heating generate about a quarter of all emissions from the burning of fossil fuels. That makes electric vehicles essential to reducing overall emissions, but how clean an electric vehicle is also depends on how the electricity is generated, the efficiency of the supply and the efficiency of the vehicle.

Scientists from the universities of Exeter, Nijmegen and Cambridge conducted lifecycle assessments that showed that even where electricity generation still involves substantial amounts of fossil fuel, there was a CO2 saving over conventional cars and fossil fuel heating.

The coronavirus pandemic is shutting down industrial activity and temporarily slashing air pollution levels around the world, satellite imagery from the European Space Agency shows.

Readings from ESA’s Sentinel-5P satellite show that over the past six weeks, levels of nitrogen dioxide (NO2) over cities and industrial clusters in Asia and Europe were markedly lower than in the same period last year.

While not a greenhouse gas itself, the pollutant originates from the same activities and industrial sectors that are responsible for a large share of the world’s carbon emissions and that drive global heating.

England is in danger of experiencing droughts within 20 years unless action is taken to combat the impact of the climate crisis on water availability, the public spending watchdog says.

Water companies will have to reduce the quantity of water they take out of rivers, lakes and the ground by more than 1bn litres a day, creating huge shortfalls in the coming decades, the NAO warned.

The total supply is forecast to drop by 7% by 2045 because of the climate crisis and the need to scale back the amount of water taken out of England’s waterways and soils.

Nature is sending us a message with the coronavirus pandemic and the ongoing climate crisis, according to the UN’s environment chief, Inger Andersen.

Leading scientists also said the Covid-19 outbreak was a “clear warning shot”, given that far more deadly diseases existed in wildlife, and that today’s civilisation was “playing with fire”. They said it was almost always human behaviour that caused diseases to spill over into humans.

They also urged authorities to put an end to live animal markets – which they called an “ideal mixing bowl” for disease – and the illegal global animal trade.

As a mental health professional, I disagree with the message in Paul Daley’s article (We face a pandemic of mental health disorders, 24 March). We’re not facing “a pandemic of severe mental health disorders”. We’re all facing entirely normal fear, anxiety, despair and confusion about a truly terrifying situation that challenges our whole way of life. Never has it been clearer that so-called “mental disorders” make sense in context. In fact, many professionals would argue that this applies to the whole range of experiences that are labelled as clinical depression, personality disorder, psychosis, and so on.

We can come out of this crisis in a better state than before by staying connected with our feelings and the urgent threats that have led to them, and taking collective action to deal with the root causes. These include climate change, environmental degradation, wildlife trafficking, insecure employment, the structure and funding of public services, and the neoliberal values that have driven us for far too long.

Unlike many news organisations, all of our reporting is free and available for everyone – during this time of crisis and beyond. This is made possible thanks to the support we receive from readers like you across America in all 50 states.

A $2tn US coronavirus relief package will dole out billions to struggling airlines and offer low-interest loans that fossil fuel companies could compete for – without requiring any action to stem the climate crisis.

The House is expected to vote on the package on Friday. It also includes nearly $500bn in lending authority that one environment group, Friends of the Earth, called a “corporate slush fund with insufficient guardrails to protect workers, taxpayers and the climate”.

In the end, the stimulus package focused on direct aid to individuals and the worst-hit industries, while setting climate considerations aside.

On March 12, 1938, German troops march into Austria to annex the German-speaking nation for the Third Reich.

Before the plebiscite could take place, however, Schuschnigg gave in to pressure from Hitler and resigned on March 11. In his resignation address, under coercion from the Nazis, he pleaded with Austrian forces not to resist a German “advance” into the country.

Austria existed as a federal state of Germany until the end of World War II, when the Allied powers declared the Anschluss void and reestablished an independent Austria. Schuschnigg, who had been imprisoned soon after resigning, was released in 1945.

As a university student, Karl Marx (1818-1883) joined a movement known as the Young Hegelians, who strongly criticized the political and cultural establishments of the day.

Karl Marx was born in 1818 in Trier, Prussia; he was the oldest surviving boy in a family of nine children. Both of his parents were Jewish, and descended from a long line of rabbis, but his father, a lawyer, converted to Lutheranism in 1816 due to contemporary laws barring Jews from higher society. Young Karl was baptized in the same church at the age of 6, but later became an atheist.

After receiving his degree, Marx began writing for the liberal democratic newspaper Rheinische Zeitung, and he became the paper’s editor in 1842. The Prussian government banned the paper as too radical the following year. With his new wife, Jenny von Westphalen, Marx moved to Paris in 1843. There Marx met fellow German émigré Friedrich Engels, who would become his lifelong collaborator and friend. In 1845, Engels and Marx published a criticism of Bauer’s Young Hegelian philosophy entitled “The Holy Father.”